Dorsal Dragons are so named because they have large fins along their backs that can be raised and lowered at will. They use these fins to regulate body temperature; they raise them to cool off when they become overheated. The bright colors on the fins double as a means of attracting mates.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

The High Warlock of Brooklyn, and in love with Alec (another guy). He is described as looking around the age of nineteen, but is really eight hundred years old, with flamboyant clothes and hair and is described as a sexy warlock. He becomes a friend to the protagonists as the books unfold. He asks Clary to find The Book of White for him, after impersonating Ragnor Fell (who is actually dead). He is also the person responsible for erasing all of Clary's early memories of Shadowhunter and demon encounters.